Conventionally, as a method and an apparatus for obtaining three-dimensional data (spatial information) indicating an external appearance of an object, a three-dimensional data obtaining apparatus disclosed in Patent Document 1 has been known. According to this three-dimensional data obtaining apparatus, it is possible to form virtual three-dimensional data of the object in a computer.
However, in the above three-dimensional data obtaining apparatus, attention is not given to displaying a stereoscopic image based on an obtained three-dimensional data of an object by using a three-dimensional image presentation technology such as computer holography. For this reason, in order to display a stereoscopic image based on an obtained three-dimensional data of an object, the above three-dimensional data obtaining apparatus needs to convert or calculate the three-dimensional data in compliance with a type and a display format of the stereoscopic image.
In order to generate a hologram for displaying a stereoscopic image of an object, technologies for recording interference fringes of light by using an image pick-up device, such as a CCD camera, are disclosed in Patent Document 2 and Non-patent Document 1.
The above technologies are configured to obtain interference fringes of light themselves by using an image pick-up device such as a CCD camera. Here, because a spatial resolution of a general CCD camera is about 5 μm, three-dimensional images, which can be obtained with the CCD camera, are limited to those within a viewing range of about 5 to 10 degrees.
For this reason, when a viewing range of a three-dimensional image intended to be reconstructed exceeds the viewing range of 5 to 10 degrees, the interference fringes of light is denser than the spatial resolution of the CCD camera. As a result, the interference fringes of light cannot be recorded with a good contrast.
That is, in each of the above technologies, there arise problems that angles, from which a stereoscopic image reconstructed by the generated hologram can be checked on, are limited, and that sizes of the respective stereoscopic images, which can be reconstructed, are limited.
In each of the above technologies, there is a problem that it is difficult to record the interference fringes of light with a simple apparatus or environment for the following reasons. A special light source, such as a laser, is necessary in order to secure coherence of a light source, and an influence, such as vibration, occurs considerably. As a result, it is necessary to apply a special treatment, such as a vibration control treatment, to an entire image reconstruction system.    (Patent Document 1) Japanese Patent Application No. 2004-37396    (Patent Document 2) Japanese Patent Application No. H9-237029    (Non-patent Document 1) Sato et al., “Recording Hologram and Reconstructing Three-dimensional Dynamic Image”, the 2004 General Conference of the Institute of Electronics, Information and Communication Engineers
As has been described above, in the conventional technologies, there are following problems. At the time when three-dimensional data is obtained, attention is not given to displaying a stereoscopic image (refer to Patent Document 1). As a result of attempting to directly obtain the interference fringes of light, the interference fringes of light cannot be obtained with a simple apparatus or environment because a high degree of precision of a device, coherence of a light source, a vibration control measure and the like are necessary (refer to Patent Document 2 and Non-patent Document 1).